Golf club head

ABSTRACT

A golf club head includes a face, a sole, a back, and a hosel. The back is connected to at least a top blade of the face and to a trailing edge of the sole to form a cavity surrounded by the face, the sole, and the back. The cavity has an opening on a toe side. The sole is shaped into a triangle whose three vertices are a heel end of the sole, a face-side toe end of the sole, and a back-side toe end of the sole. The heel end is a point where a central axis of a bore of the hosel into which a shaft is to be inserted intersects with the sole. The face-side toe end is a point closest to a toe in a region where the sole connects to the face. The back-side toe end is the toe-side end of the trailing edge.

CROSS-REFERENCE TO RELATED APPLICATION

This application is based upon and claims priority to Japanese Patent Application No. 2017-230772, filed on Nov. 30, 2017, the entire contents of which are incorporated herein by reference.

BACKGROUND OF THE INVENTION 1. Field of the Invention

The present invention relates to golf club heads.

2. Description of the Related Art

In conventional golf club heads, attempts have been made to reduce weight and also increase sole width by hollowing out the back of a club head as in, for example, cavity back irons. (See, for example, Japanese Patent No. 3658293, Japanese Patent No. 3172116, Japanese Design Registration No. 1535988, Japanese Patent No. 4630566, and Japanese Laid-Open Patent Publication No. 7-255883.)

SUMMARY OF THE INVENTION

According to an aspect of the present invention, a golf club head includes a face, a sole, a back, and a hosel. The back is connected to at least a top blade of the face and to the trailing edge of the sole to form a cavity surrounded by the face, the sole, and the back. The cavity has an opening on a toe side. The sole is shaped into a triangle whose three vertices are a heel end of the sole, a face-side toe end of the sole, and a back-side toe end of the sole. The heel end is a point where a central axis of a bore of the hosel into which a shaft is to be inserted intersects with the sole. The face-side toe end is a point closest to a toe in a region where the sole connects to the face. The back-side toe end is the toe-side end of the trailing edge.

The object and advantages of the invention will be realized and attained by means of the elements and combinations particularly pointed out in the claims.

It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory and not restrictive of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a front elevational view of a golf club head according to an embodiment;

FIG. 2 is a rear elevational view of the golf club head according to the embodiment;

FIG. 3 is a top plan view of the golf club head according to the embodiment;

FIG. 4 is a bottom plan view of the golf club head according to the embodiment;

FIG. 5 is a left-side view of the golf club head according to the embodiment;

FIG. 6 is a right-side view of the golf club head according to the embodiment;

FIG. 7 is a diagram illustrating the rear side of the golf club head according to the embodiment;

FIG. 8 is another diagram illustrating the rear side of the golf club head according to the embodiment;

FIG. 9 is a diagram illustrating a sole shape of the golf club head according to the embodiment;

FIG. 10 is a diagram illustrating a back shape of the golf club head according to the embodiment;

FIG. 11 is a diagram illustrating a cavity shape of the golf club head according to the embodiment; and

FIG. 12 is a top plan view of a golf club head according to a variation of the embodiment.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

As described above, attempts have been made to reduce weight and also increase sole width in conventional golf club heads. It has been difficult, however, to further increase sole width while reducing weight.

According to an aspect of the present invention, a golf club head increased in sole width while reduced in weight is provided.

One or more embodiments are described below with reference to the accompanying drawings. In the following description, the same elements are referred to using the same reference numeral, and duplicate description thereof may be omitted.

FIGS. 1, 2, 3, 4, 5 and 6 are a front elevational view, a rear elevational view, a top plan view, a bottom plan view, a left-side (toe-side) view and a right-side (heel-side) view, respectively, of a golf club head 1 according to an embodiment.

The front elevational view of FIG. 1 is a view taken from the side of a face surface 10 f of the golf club head 1 (that is, looking at the face surface 11 f), depicting the golf club head 1 resting (soled) on a horizontal plane at a reference lie angle and a reference loft angle. Furthermore, in the drawings, the double-headed arrow d1 indicates the “toe-heel” (left-right) direction, namely, the direction from the toe side to the heel side or the direction from the heel side to the toe side, of the golf club head 1, the double-headed arrow d2 indicates the “top-sole” (up-down) direction, namely, the direction from the top side to the sole side or the direction from the sole side to the top side, of the golf club head 1, and the double-headed arrow d3 indicates the “face-back” (front-rear) direction, namely, the direction from the face side to the back side or the direction from the back side to the face side, of the golf club head 1.

The golf club head 1 depicted in FIGS. 1 through 6 is an iron-type golf club head, and includes a face 10, a sole 20, a back 30, and a hosel 40. The golf club head 1 may be made using a metal material such as a titanium alloy, titanium, soft iron, stainless steel, or an aluminum alloy. With respect to each constituent part of the golf club head 1, a surface on the face side may be referred to as “front surface” and a surface on the back side may be referred to as “rear surface.”

The face 10 includes the face surface 10 f, which serves a ball-striking surface. The face 10 has a predetermined thickness. The face surface 10 f defines the front surface of the face 10. Multiple score lines 10 s (grooves depressed from the face surface 10 f) elongated in the toe-heel direction are arranged at predetermined intervals in the top-sole direction in the face surface 10 f.

The sole 20 defines a bottom portion of the golf club head 1. The back 30 is a portion connecting (extending between) the face 10 and the sole 20. The hosel 40 receives a shaft.

FIGS. 7 and 8 are diagrams illustrating the rear side of the golf club head 1 according to this embodiment. FIGS. 9 and 10 are diagrams illustrating a sole shape and a back shape, respectively, of the golf club head 1 according to this embodiment.

Constituent parts of the golf club head 1 are described in detail below with reference to FIGS. 7 through 10 in addition to FIGS. 1 through 6.

The sole 20 is shaped into a triangle whose three vertices are a heel end 20P1 of the sole 20, a face-side toe end 20P2 of the sole 20, and a back-side toe end 20P3 of the sole 20. The heel end 20P1 is a point at which a central axis L1 of the bore of the hosel 40 into which a shaft is to be inserted intersects with the sole 20. The face-side toe end 20P2 is the point closest to the toe in a region where the sole 20 connects to the face 10. The back-side toe end 20P3 is the toe-side end of the trailing edge 20 t.

The back 30 connects to at least part of a top blade 10 t, which is the upper end of the face 10, and a trailing edge 20 t of the sole 20. The back 30 may extend from the top blade 10 t of the face 10 to the leading edge 101 side of the rear surface of the face 10.

The back 30 is shaped into a triangle whose three vertices are a heel end 30P1 of the back 30, a sole-side toe end 30P2 of the back 30, and a face-side toe end 30P3 of the back 30. The heel end 30P1 is the point closest to the heel in a region where the back 30 connects to the sole 20. The sole-side toe end 30P2 is the point closest to the sole 20 and to the toe in the region where the back 30 connects to the sole 20. The face-side toe end 30P3 is the point closest to the toe in a region where the back 30 connects to the face 10.

According to embodiments of the present invention, the term “triangle” includes not only a perfect triangle but also a substantial triangle. The substantial triangle refers to a shape defined by a base and two oblique sides where, for example, one or more of its three vertices are chamfered or rounded, the base and the two oblique sides are curved lines or a combination of straight and curved lines, or each of one or more of the base and the two oblique sides is a combination of straight and curved lines.

According to the golf club head 1, because the back 30 is provided to reinforce the sole 20, the sole 20 can be reduced in thickness. As a result, it is possible to reduce unnecessary vibrations of the sole 20 at the time of striking a ball to improve an impact feeling and an impact sound.

According to the golf club head 1, the thickness of the face 10, the sole 20, and the back 30 becomes smallest in a portion of the sole 20. As a result, it is possible to raise the center of gravity of the golf club head 1 by reducing the weight of the sole 20, and accordingly, to increase the amount of backspin of a golf ball struck with the golf club head 1.

Conversely, to lower the center of gravity of the golf club head 1, it is possible to increase the thickness of the sole 20 or reduce the thickness of the back 30 instead of increasing the thickness of the sole 20. That is, the thickness of the face 10, the sole 20, and the back 30 may become smallest in a portion of the back 30.

The face 10, the sole 20, and the back 30 form a cavity 50. The cavity 50 is a hollow (space) surrounded by the face 10, the sole 20, and the back 30, and has a triangular opening on its toe side.

The cross-sectional area of the cavity 50 in the face-back direction maximizes on the toe side and gradually decreases toward the heel. This makes it possible to hide the sole 20 behind the face 10 as much as possible at address, and to increase the width of the sole 20 in the face-back direction. The cross-sectional area of the cavity 50 in the face-back direction refers to the area of a space surrounded by the face 10, the sole 20, and the back 30 in a plane cutting through the cavity 50 in the face-back direction.

FIG. 11 is a diagram illustrating a shape of the cavity 50 of the golf club head 1 according to this embodiment, depicting the golf club head 1 resting (soled) on a horizontal plane H (corresponding to a ground surface) at a reference lie angle and a reference loft angle.

Referring to FIG. 11, a straight line L2 that passes through the leading edge 101 to extend in the top-sole direction perpendicularly to the horizontal plane H and a straight line L3 that passes through the back-side toe end 20P3 of the sole 20 to extend in the top-sole direction perpendicularly to the horizontal plane H are defined. Here, letting a maximum projection length L4 of the face 10 in the face-back direction be 1, a length L5 of the distance between the straight lines L2 and L3 in the face-back direction (the distance between the leading edge 101 and the back-side toe end 20P3 of the sole 20 in the face-back direction) is 0.75 or more. That is, the golf club head 1 achieves the sole 20 that is wide in the face-back direction.

As illustrated in FIG. 3, when the golf club head 1 is soled on a horizontal plane at a reference lie angle and a reference loft angle, the projection of the sole 20 from above may protrude from the face 10. In this case, at least a portion of the sole 20 protruding from the face 10 (indicated by a dot pattern in FIG. 3) is preferably painted with a blackish color. Here, examples of blackish colors include black; dark colors similar to black, such as dark brown, dark red, dark green, dark blue, and dark purple; and mixtures of two or more of these colors. When the face 10 is originally black, the protruding portion protruding from the face 10 may be painted with a color different from black.

By causing at least a portion of the sole 20 whose projection protrudes from the face 10 to differ in color from the face 10, it is possible to make the sole 20 (the trailing edge 20 t) difficult for a user of the golf club head 1 to see at address. As a result, it is possible to cause the golf club head 1 to be closer in appearance to conventional iron faces. Therefore, it is possible to prevent a user of the golf club head 1 from having a feeling of strangeness.

FIG. 12 is a top plan view illustrating a golf club head 1A according to a variation of this embodiment. As illustrated in FIG. 12, the projection of the sole 20 from above may be completely hidden by the face 10 when the golf club head 1A is soled on a horizontal plane at a reference lie angle and a reference loft angle. Whether to adopt the configuration of FIG. 3 or the configuration of FIG. 12 may be suitably determined in accordance with required specifications. For example, whether to adopt the configuration of FIG. 3 or the configuration of FIG. 12 may be determined based on one or both of the club number (loft angle) of a golf club head and the shape of the projection of the face of the golf club head at address.

The above-described golf club heads 1 and 1A of this embodiment provide stability and a sense of ease at address, thus providing their users with the impression that the users are less likely to miss a shot.

Furthermore, the sole 20 and the back 30 are wider in the face-back direction. Therefore, when striking a golf ball with the golf club head 1 or 1A, the leading edge 101 is less likely to stick into the ground, thus allowing the sole 20 to more easily slide on the ground surface.

Furthermore, according to the golf club heads 1 and 1A, the sole 20 is not provided on the toe side, and the cavity 50 has a hollow shape. This makes it possible to prevent an increase in the weight of the golf club heads 1 and 1A even in the case of increasing the projection area of the face 10 by increasing the width of the sole 20 in the face-back direction.

All examples and conditional language provided herein are intended for pedagogical purposes of aiding the reader in understanding the invention and the concepts contributed by the inventor to further the art, and are not to be construed as limitations to such specifically recited examples and conditions, nor does the organization of such examples in the specification relate to a showing of the superiority or inferiority of the invention. Although one or more embodiments of the present invention have been described in detail, it should be understood that the various changes, substitutions, and alterations could be made hereto without departing from the spirit and scope of the invention. 

What is claimed is:
 1. A golf club head comprising: a face; a sole; a back connected to at least a top blade of the face and to a trailing edge of the sole to form a cavity surrounded by the face, the sole, and the back, the cavity having an opening on a side of a toe of the golf club head; and a hosel, wherein the sole is shaped into a triangle whose three vertices are a heel end of the sole, a face-side toe end of the sole, and a back-side toe end of the sole, the heel end being a point at which a central axis of a bore of the hosel into which a shaft is to be inserted intersects with the sole, the face-side toe end being a point closest to the toe in a region where the sole connects to the face, the back-side toe end being an end of the trailing edge on the side of the toe.
 2. The golf club head as claimed in claim 1, wherein a projection of the sole from above is completely hidden by the face when the golf club head is soled on a horizontal plane at a reference lie angle and a reference loft angle.
 3. The golf club head as claimed in claim 1, wherein a color of at least a portion of the sole whose projection protrudes from the face when the golf club head is soled on a horizontal plane at a reference lie angle and a reference loft angle is different from a color of the face.
 4. The golf club head as claimed in claim 1, wherein a cross-sectional area of the cavity in a face-back direction maximizes on the side of the toe and gradually decreases toward a heel of the golf club head.
 5. The golf club head as claimed in claim 1, wherein the back is shaped into a triangle whose three vertices are a heel end of the back, a sole-side toe end of the back, and a face-side toe end of the back.
 6. The golf club head as claimed in claim 5, wherein the heel end of the back is a point closest to a heel of the golf club head in a region where the back connects to the sole, the sole-side toe end of the back is a point closest to the sole and to the toe in the region where the back connects to the sole, and the face-side toe end of the back is a point closest to the toe in a region where the back connects to the face.
 7. The golf club head as claimed in claim 1, wherein a thickness of the face, the sole, and the back is smallest in a portion of the sole.
 8. The golf club head as claimed in claim 1, wherein a thickness of the face, the sole, and the back is smallest in a portion of the back.
 9. The golf club head as claimed in claim 1, wherein, when the golf club head is soled on a horizontal plane at a reference lie angle and a reference loft angle, letting a maximum projection length of the face in a face-back direction be 1, a length of a distance between a first line and a second line in the face-back direction is 0.75 or more, where the first line is a straight line that passes through a leading edge of the face to extend in a top-sole direction perpendicularly to the horizontal plane and the second line is a straight line that passes through the back-side toe end of the sole to extend in the top-sole direction perpendicularly to the horizontal plane. 